i drive a 2013 Accord EX 2.4L, CVT. I bought it used in feb 2023 with 79k on the dash. Ran well, no issues, no dummy lights, and a well kept interior. After purchasing the vehicle I ran into a small, and seemingly impossible issue to resolve; a slightly rough idle (definitely abnormal) where the rpm’s will drop maybe 75-100 or so only at OT and when I am at a complete stop, in drive. When I change to Neutral, the rattling noise I hear and shaking seats, disappear, so I typically switch to neutral when it can. I have gone through many different diagnostics and replaced many parts such as my Air filter, spark plugs, and pcv. cleaned my throttle, Mass airflow sensor and battery terminals. I also used a rislone cat complete fuel additive which I followed to a t. Nothing has helped the issue resolve and I don’t want to go to the dealer yet. I thought it was maybe the EGR valve but from everything I’ve seen, this vehicle doesn’t have one. Someone Please help me figure out what is wrong! Thank you! If any more information is needed to help paint a clearer picture, I am more than happy to answer all questions.